1. Field of the Invention
The present invention relates to a switched current memory cell adaptive to a current mode serial-to-parallel converter or a current mode parallel-to-serial converter of an OFDM system and, more particularly, to a switched current memory cell capable of reducing power consumption by cutting off unnecessary current in a hold mode of a single line or double line memory cell.
2. Description of the Related Art
In general, an orthogonal frequency division multiplexing (OFDM) communication scheme is used to accomplish high speed communications of 20 Mbps or faster, and such OFDM communication scheme realizing high speed communications of 20 Mps or faster is making rapid progress as a 4th-generation communication scheme beyond IMT-2000.
In a wireless communication system using the OFDM system, a baseband signal processing unit consumes power of about 300 mW or more for an A/D converter, a D/A converter, and a DSP (Digital System Processing) FFT (Fast Fourier Transform) LSI, which poses an obstacle to the wireless communication system.
Meanwhile, in the OFDM system, an analog Fourier Transform LSI using a current mode has been proposed as a solution to power consumption, and in order to employ such signal processing method, a memory cell, compared with a voltage memory cell, is considered to be suitable for a serial-to-parallel converter or parallel-to-serial converter, and as such the memory cell receives much attention.
The related art current memory cell is configured as a single line or double line memory cell. The single line current memory cell is formed as a circuit including a single current path from a power source stage to a ground stage, and the double line current memory cell is formed as a circuit including two current paths from the power source stage to the ground stage.
However, in the related art current memory cell including a sampling mode in which an input current is sampled, a hold mode in which a sampled current is stored and maintained, and an output mode in which the stored current is outputted, current flows continuously across the memory cell in the hold mode, resulting in a waste of current.